JMich: H.P. Lovecraft's and Shakespeare's works aren't legally abandonware, they are in the public domain.
Not entirely true. They might be public domain in the USA, but in many other countries, much of the work they (and others) did is still covered by copyright - either due to "modern" translations (say the last 20-30 years), renewed copyrights (ie by the regional publisher) or localised copyright law. Hence both archive.org and Project Gitenberg have warnings regarding the public domain status of what they offer.
I know this from personal experience as well - due to some work (comission) I did last year based on a supposedly "public domain" Lovecraft tale, and the ensuing legal battle. Can't say much more than that, but if you think something is public domain and wish to make use of it - best to check first... REALLY check!